We are studying metabolic changes which occur as an individual develops from a fetus to a mature adult. We are currently focusing on two areas: 1) monthly gonadotropin cycles in premenarchial girls and pubescent boys utilizing radioimmunoassay methods for measuring urinary lutenizing hormone and urinary follicle stimulating hormone and analyzing the data with autoregressive computer techniques, and 2) mineral metabolism in the monkey fetus and human newborn. Calcium kinetics are studied in the patients using stable calcium isotopes analyzed in the laboratory by mass spectroscopy. Physiological effects of calcium are studied by measurements of ionized calcium in the blood and in cerebrospinal fluid. Trace element (zinc and copper) analyses are performed by atomic absorption spectrophotometry as part of our studies of nutritional aspects of mineral metabolism in the newborn. BIBLIOGRAPHIC REFERENCE: Pollard,Harvard B., Creutz, C., Christopher, J., Pazoles and Hansen, J.: Calcium chelating properties of monovalent anions commonly used to substitute for chloride in physiological salt solutions. Anal. Biochem., in press, 1977.